GLM-5.3

Z.ai's 2026-08-14 coding model, pitched as the strongest open-weights coder on the market. At 743B parameters, it reuses the GLM-5.2 base model with all gains coming from expanded post-training ("more environments, more diverse tasks, more compute"), and keeps the 1M-token context and 128K output ceiling while consuming far fewer tokens per task. Live at launch through the GLM Coding Plan subscription and ZCode, with API access following. Open weights shipped 2026-08-28 on Hugging Face (zai-org/GLM-5.3) after a roughly two-week safety review that Z.ai attributed to unexpectedly strong multi-stage exploit-chaining behavior surfaced during evaluation (2,436 vulnerabilities found across 269 open-source projects). Unlike GLM-5.3-Flash's plain MIT, the flagship weights carry a bespoke "GLM-5.3 License": MIT-equivalent grants (use, modify, distribute, sell without restriction) for most users, with one divergence — companies whose aggregate revenue exceeds $10B over any consecutive 12 months must pass Z.AI's security review before using the weights or derivatives commercially as a Model-as-a-Service.